Tonagura!, Mikakunin de Shinkoukei Recommendations
Both are love comedies. The setting is a bit similar, however characters personalities are a bit opposite. In both animes the guy moves in to the girl's house with his little sister. In tonagura, they were neighbors, but technically it was the same since they have to eat and spend most of the time on the girl's house. In both animes the main girl has an inferiority complex with her older sister. In both, the main girl's Older sister teases the guy's little sister, who is afraid of her as result.